由于我并不经常运行这些命令，因此我无法确定具体发生时间。鉴于我问了这个问题，一般 DNS 解析肯定是有效的。
我在这个网站上看到过类似的问题，但答案似乎不适用。据我所知，只有 dig 和 nslookup 受到影响。wget 和 curl 都能够解析 URL。
adam@latitude-7400:~$ nslookup
nslookup: symbol lookup error: /lib/x86_64-linux-gnu/libisc.so.1601: undefined symbol: deflate
adam@latitude-7400:~$ dig
dig: symbol lookup error: /lib/x86_64-linux-gnu/libisc.so.1601: undefined symbol: deflate
adam@latitude-7400:~$ ldd /lib/x86_64-linux-gnu/libisc.so.1601
linux-vdso.so.1 (0x00007fff7a472000)
libcrypto.so.1.1 => /lib/x86_64-linux-gnu/libcrypto.so.1.1 (0x00007f0b01921000)
libuv.so.1 => /lib/x86_64-linux-gnu/libuv.so.1 (0x00007f0b018f0000)
libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f0b018cd000)
libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f0b018c7000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f0b016d5000)
/lib64/ld-linux-x86-64.so.2 (0x00007f0b01c82000)
adam@latitude-7400:~$ ls -l /lib/x86_64-linux-gnu/libisc.so.1601
lrwxrwxrwx 1 root root 18 Oct 27 12:00 /lib/x86_64-linux-gnu/libisc.so.1601 -> libisc.so.1601.0.0
adam@latitude-7400:~$ sudo apt reinstall dnsutils
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages were automatically installed and are no longer required:
chromium-codecs-ffmpeg-extra gstreamer1.0-vaapi libgstreamer-plugins-bad1.0-0 libva-wayland2
linux-headers-5.11.0-37-generic linux-hwe-5.11-headers-5.11.0-37 linux-image-5.11.0-37-generic
linux-modules-5.11.0-37-generic linux-modules-extra-5.11.0-37-generic
Use 'sudo apt autoremove' to remove them.
The following NEW packages will be installed:
dnsutils
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 2,756 B of archives.
After this operation, 47.1 kB of additional disk space will be used.
Get:1 http://ie.archive.ubuntu.com/ubuntu focal-updates/universe amd64 dnsutils all 1:9.16.1-0ubuntu2.9 [2,756 B]
Fetched 2,756 B in 0s (12.5 kB/s)
Selecting previously unselected package dnsutils.
(Reading database ... 299655 files and directories currently installed.)
Preparing to unpack .../dnsutils_1%3a9.16.1-0ubuntu2.9_all.deb ...
Unpacking dnsutils (1:9.16.1-0ubuntu2.9) ...
Setting up dnsutils (1:9.16.1-0ubuntu2.9) ...
adam@latitude-7400:~$ dig
dig: symbol lookup error: /lib/x86_64-linux-gnu/libisc.so.1601: undefined symbol: deflate
adam@latitude-7400:~$ nslookup
nslookup: symbol lookup error: /lib/x86_64-linux-gnu/libisc.so.1601: undefined symbol: deflate